c# 邮件发送

  public enum MailFormat
        {
            /// <summary>
            /// None
            /// </summary>
            None = 0,
            /// <summary>
            /// Text
            /// </summary>
            Text = 1,
            /// <summary>
            /// Html
            /// </summary>
            Html = 2
        }

        public static void SendMail(ArrayList to, string from, string subject, string body)
        {
            if (to.Count <= 0)
                throw new ArgumentException("The adressee of mail is not specified", "to");
            if (string.IsNullOrEmpty(subject))
                throw new ArgumentException("The subject of mail is not specified", "subject");
            if (string.IsNullOrEmpty(body))
                throw new ArgumentException("The body of mail is not specified", "body");
            string From = from.Length > 0 ? from : "[e-mail]";
            string SMTPServer = "smtp.163.com";
            int SMTPPort = 25;
            bool SMTPAuthentictation = true;
            bool SMTPUseSSL = false;
            string SMTPUsername = "[e-mail]";
            string SMTPPassword = "************";
            SendMail(to, From, subject, body, System.Text.Encoding.UTF8,
                MailPriority.Normal, MailFormat.Html, SMTPServer, SMTPPort,
                SMTPUseSSL, SMTPAuthentictation, SMTPUsername, SMTPPassword);
        }

        /// <summary>
        /// Sends mail using the standard .net 2.0 System.Net.Mail classes
        /// </summary>
        /// <param name="to">To.</param>
        /// <param name="from">From.</param>
        /// <param name="subject">The subject.</param>
        /// <param name="body">The body.</param>
        /// <param name="bodyEncoding">The body encoding.</param>
        /// <param name="priority">The priority.</param>
        /// <param name="bodyFormat">The body format.</param>
        /// <param name="smtpServer">The SMTP server.</param>
        /// <param name="smtpPort">The SMTP port.</param>
        /// <param name="smtpUseSSL">if set to <c>true</c> [SMTP use SSL].</param>
        /// <param name="smtpAuthentication">if set to <c>true</c> [SMTP authentication].</param>
        /// <param name="smtpUsername">The SMTP username.</param>
        /// <param name="smtpPassword">The SMTP password.</param>
        public static void SendMail(ArrayList to, string from, string subject, string body, System.Text.Encoding bodyEncoding, MailPriority priority, MailFormat bodyFormat,
            string smtpServer, int smtpPort, bool smtpUseSSL,
            bool smtpAuthentication, string smtpUsername, string smtpPassword)
        {
            if (to.Count <= 0)
                throw new ArgumentException("The receiver of the mail message is not specified", "to");
            if (string.IsNullOrEmpty(from))
                throw new ArgumentException("The sender of the mail message is not specified", "from");
            if (string.IsNullOrEmpty(subject))
                throw new ArgumentException("The subject of the mail message is not specified", "subject");
            if (string.IsNullOrEmpty(body))
                throw new ArgumentException("The body of the mail message is not specified", "body");
            if (string.IsNullOrEmpty(smtpServer))
                throw new ArgumentException("The smtp server is not specified", "smtpServer");

            try
            {
                MailMessage msg = new MailMessage();
                foreach (string tos in to)
                {
                    msg.To.Add(new MailAddress(tos.ToString()));
                }
                msg.From = new MailAddress(from);
                msg.Priority = priority;
                msg.IsBodyHtml = bodyFormat == MailFormat.Html ? true : false;
                msg.BodyEncoding = System.Text.Encoding.UTF8;
                msg.Body = body;
                msg.Subject = subject;

                SmtpClient smtp = new SmtpClient();
                smtp.Host = smtpServer;
                smtp.Port = smtpPort;
                smtp.EnableSsl = smtpUseSSL;

                if (smtpAuthentication)
                    smtp.Credentials = new NetworkCredential(smtpUsername, smtpPassword);

                smtp.Send(msg);
            }
            catch (Exception ex)
            {
            }
        }